Commit | Line | Data |
---|---|---|
97e873e5 SR |
1 | /* |
2 | * Procedures for creating, accessing and interpreting the device tree. | |
3 | * | |
4 | * Paul Mackerras August 1996. | |
5 | * Copyright (C) 1996-2005 Paul Mackerras. | |
6 | * | |
7 | * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. | |
8 | * {engebret|bergner}@us.ibm.com | |
9 | * | |
10 | * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net | |
11 | * | |
12 | * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell. | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or | |
15 | * modify it under the terms of the GNU General Public License | |
16 | * as published by the Free Software Foundation; either version | |
17 | * 2 of the License, or (at your option) any later version. | |
18 | */ | |
19 | #include <linux/module.h> | |
20 | #include <linux/of.h> | |
581b605a SR |
21 | #include <linux/spinlock.h> |
22 | ||
1ef4d424 SR |
23 | struct device_node *allnodes; |
24 | ||
581b605a SR |
25 | /* use when traversing tree through the allnext, child, sibling, |
26 | * or parent members of struct device_node. | |
27 | */ | |
28 | DEFINE_RWLOCK(devtree_lock); | |
97e873e5 SR |
29 | |
30 | int of_n_addr_cells(struct device_node *np) | |
31 | { | |
32 | const int *ip; | |
33 | ||
34 | do { | |
35 | if (np->parent) | |
36 | np = np->parent; | |
37 | ip = of_get_property(np, "#address-cells", NULL); | |
38 | if (ip) | |
39 | return *ip; | |
40 | } while (np->parent); | |
41 | /* No #address-cells property for the root node */ | |
42 | return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; | |
43 | } | |
44 | EXPORT_SYMBOL(of_n_addr_cells); | |
45 | ||
46 | int of_n_size_cells(struct device_node *np) | |
47 | { | |
48 | const int *ip; | |
49 | ||
50 | do { | |
51 | if (np->parent) | |
52 | np = np->parent; | |
53 | ip = of_get_property(np, "#size-cells", NULL); | |
54 | if (ip) | |
55 | return *ip; | |
56 | } while (np->parent); | |
57 | /* No #size-cells property for the root node */ | |
58 | return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; | |
59 | } | |
60 | EXPORT_SYMBOL(of_n_size_cells); | |
61 | ||
581b605a SR |
62 | struct property *of_find_property(const struct device_node *np, |
63 | const char *name, | |
64 | int *lenp) | |
65 | { | |
66 | struct property *pp; | |
67 | ||
64e4566f TT |
68 | if (!np) |
69 | return NULL; | |
70 | ||
581b605a SR |
71 | read_lock(&devtree_lock); |
72 | for (pp = np->properties; pp != 0; pp = pp->next) { | |
73 | if (of_prop_cmp(pp->name, name) == 0) { | |
74 | if (lenp != 0) | |
75 | *lenp = pp->length; | |
76 | break; | |
77 | } | |
78 | } | |
79 | read_unlock(&devtree_lock); | |
80 | ||
81 | return pp; | |
82 | } | |
83 | EXPORT_SYMBOL(of_find_property); | |
84 | ||
97e873e5 SR |
85 | /* |
86 | * Find a property with a given name for a given node | |
87 | * and return the value. | |
88 | */ | |
89 | const void *of_get_property(const struct device_node *np, const char *name, | |
90 | int *lenp) | |
91 | { | |
92 | struct property *pp = of_find_property(np, name, lenp); | |
93 | ||
94 | return pp ? pp->value : NULL; | |
95 | } | |
96 | EXPORT_SYMBOL(of_get_property); | |
0081cbc3 SR |
97 | |
98 | /** Checks if the given "compat" string matches one of the strings in | |
99 | * the device's "compatible" property | |
100 | */ | |
101 | int of_device_is_compatible(const struct device_node *device, | |
102 | const char *compat) | |
103 | { | |
104 | const char* cp; | |
105 | int cplen, l; | |
106 | ||
107 | cp = of_get_property(device, "compatible", &cplen); | |
108 | if (cp == NULL) | |
109 | return 0; | |
110 | while (cplen > 0) { | |
111 | if (of_compat_cmp(cp, compat, strlen(compat)) == 0) | |
112 | return 1; | |
113 | l = strlen(cp) + 1; | |
114 | cp += l; | |
115 | cplen -= l; | |
116 | } | |
117 | ||
118 | return 0; | |
119 | } | |
120 | EXPORT_SYMBOL(of_device_is_compatible); | |
e679c5f4 | 121 | |
834d97d4 JB |
122 | /** |
123 | * of_device_is_available - check if a device is available for use | |
124 | * | |
125 | * @device: Node to check for availability | |
126 | * | |
127 | * Returns 1 if the status property is absent or set to "okay" or "ok", | |
128 | * 0 otherwise | |
129 | */ | |
130 | int of_device_is_available(const struct device_node *device) | |
131 | { | |
132 | const char *status; | |
133 | int statlen; | |
134 | ||
135 | status = of_get_property(device, "status", &statlen); | |
136 | if (status == NULL) | |
137 | return 1; | |
138 | ||
139 | if (statlen > 0) { | |
140 | if (!strcmp(status, "okay") || !strcmp(status, "ok")) | |
141 | return 1; | |
142 | } | |
143 | ||
144 | return 0; | |
145 | } | |
146 | EXPORT_SYMBOL(of_device_is_available); | |
147 | ||
e679c5f4 SR |
148 | /** |
149 | * of_get_parent - Get a node's parent if any | |
150 | * @node: Node to get parent | |
151 | * | |
152 | * Returns a node pointer with refcount incremented, use | |
153 | * of_node_put() on it when done. | |
154 | */ | |
155 | struct device_node *of_get_parent(const struct device_node *node) | |
156 | { | |
157 | struct device_node *np; | |
158 | ||
159 | if (!node) | |
160 | return NULL; | |
161 | ||
162 | read_lock(&devtree_lock); | |
163 | np = of_node_get(node->parent); | |
164 | read_unlock(&devtree_lock); | |
165 | return np; | |
166 | } | |
167 | EXPORT_SYMBOL(of_get_parent); | |
d1cd355a | 168 | |
f4eb0107 ME |
169 | /** |
170 | * of_get_next_parent - Iterate to a node's parent | |
171 | * @node: Node to get parent of | |
172 | * | |
173 | * This is like of_get_parent() except that it drops the | |
174 | * refcount on the passed node, making it suitable for iterating | |
175 | * through a node's parents. | |
176 | * | |
177 | * Returns a node pointer with refcount incremented, use | |
178 | * of_node_put() on it when done. | |
179 | */ | |
180 | struct device_node *of_get_next_parent(struct device_node *node) | |
181 | { | |
182 | struct device_node *parent; | |
183 | ||
184 | if (!node) | |
185 | return NULL; | |
186 | ||
187 | read_lock(&devtree_lock); | |
188 | parent = of_node_get(node->parent); | |
189 | of_node_put(node); | |
190 | read_unlock(&devtree_lock); | |
191 | return parent; | |
192 | } | |
193 | ||
d1cd355a SR |
194 | /** |
195 | * of_get_next_child - Iterate a node childs | |
196 | * @node: parent node | |
197 | * @prev: previous child of the parent node, or NULL to get first | |
198 | * | |
199 | * Returns a node pointer with refcount incremented, use | |
200 | * of_node_put() on it when done. | |
201 | */ | |
202 | struct device_node *of_get_next_child(const struct device_node *node, | |
203 | struct device_node *prev) | |
204 | { | |
205 | struct device_node *next; | |
206 | ||
207 | read_lock(&devtree_lock); | |
208 | next = prev ? prev->sibling : node->child; | |
209 | for (; next; next = next->sibling) | |
210 | if (of_node_get(next)) | |
211 | break; | |
212 | of_node_put(prev); | |
213 | read_unlock(&devtree_lock); | |
214 | return next; | |
215 | } | |
216 | EXPORT_SYMBOL(of_get_next_child); | |
1ef4d424 SR |
217 | |
218 | /** | |
219 | * of_find_node_by_path - Find a node matching a full OF path | |
220 | * @path: The full path to match | |
221 | * | |
222 | * Returns a node pointer with refcount incremented, use | |
223 | * of_node_put() on it when done. | |
224 | */ | |
225 | struct device_node *of_find_node_by_path(const char *path) | |
226 | { | |
227 | struct device_node *np = allnodes; | |
228 | ||
229 | read_lock(&devtree_lock); | |
230 | for (; np; np = np->allnext) { | |
231 | if (np->full_name && (of_node_cmp(np->full_name, path) == 0) | |
232 | && of_node_get(np)) | |
233 | break; | |
234 | } | |
235 | read_unlock(&devtree_lock); | |
236 | return np; | |
237 | } | |
238 | EXPORT_SYMBOL(of_find_node_by_path); | |
239 | ||
240 | /** | |
241 | * of_find_node_by_name - Find a node by its "name" property | |
242 | * @from: The node to start searching from or NULL, the node | |
243 | * you pass will not be searched, only the next one | |
244 | * will; typically, you pass what the previous call | |
245 | * returned. of_node_put() will be called on it | |
246 | * @name: The name string to match against | |
247 | * | |
248 | * Returns a node pointer with refcount incremented, use | |
249 | * of_node_put() on it when done. | |
250 | */ | |
251 | struct device_node *of_find_node_by_name(struct device_node *from, | |
252 | const char *name) | |
253 | { | |
254 | struct device_node *np; | |
255 | ||
256 | read_lock(&devtree_lock); | |
257 | np = from ? from->allnext : allnodes; | |
258 | for (; np; np = np->allnext) | |
259 | if (np->name && (of_node_cmp(np->name, name) == 0) | |
260 | && of_node_get(np)) | |
261 | break; | |
262 | of_node_put(from); | |
263 | read_unlock(&devtree_lock); | |
264 | return np; | |
265 | } | |
266 | EXPORT_SYMBOL(of_find_node_by_name); | |
267 | ||
268 | /** | |
269 | * of_find_node_by_type - Find a node by its "device_type" property | |
270 | * @from: The node to start searching from, or NULL to start searching | |
271 | * the entire device tree. The node you pass will not be | |
272 | * searched, only the next one will; typically, you pass | |
273 | * what the previous call returned. of_node_put() will be | |
274 | * called on from for you. | |
275 | * @type: The type string to match against | |
276 | * | |
277 | * Returns a node pointer with refcount incremented, use | |
278 | * of_node_put() on it when done. | |
279 | */ | |
280 | struct device_node *of_find_node_by_type(struct device_node *from, | |
281 | const char *type) | |
282 | { | |
283 | struct device_node *np; | |
284 | ||
285 | read_lock(&devtree_lock); | |
286 | np = from ? from->allnext : allnodes; | |
287 | for (; np; np = np->allnext) | |
288 | if (np->type && (of_node_cmp(np->type, type) == 0) | |
289 | && of_node_get(np)) | |
290 | break; | |
291 | of_node_put(from); | |
292 | read_unlock(&devtree_lock); | |
293 | return np; | |
294 | } | |
295 | EXPORT_SYMBOL(of_find_node_by_type); | |
296 | ||
297 | /** | |
298 | * of_find_compatible_node - Find a node based on type and one of the | |
299 | * tokens in its "compatible" property | |
300 | * @from: The node to start searching from or NULL, the node | |
301 | * you pass will not be searched, only the next one | |
302 | * will; typically, you pass what the previous call | |
303 | * returned. of_node_put() will be called on it | |
304 | * @type: The type string to match "device_type" or NULL to ignore | |
305 | * @compatible: The string to match to one of the tokens in the device | |
306 | * "compatible" list. | |
307 | * | |
308 | * Returns a node pointer with refcount incremented, use | |
309 | * of_node_put() on it when done. | |
310 | */ | |
311 | struct device_node *of_find_compatible_node(struct device_node *from, | |
312 | const char *type, const char *compatible) | |
313 | { | |
314 | struct device_node *np; | |
315 | ||
316 | read_lock(&devtree_lock); | |
317 | np = from ? from->allnext : allnodes; | |
318 | for (; np; np = np->allnext) { | |
319 | if (type | |
320 | && !(np->type && (of_node_cmp(np->type, type) == 0))) | |
321 | continue; | |
322 | if (of_device_is_compatible(np, compatible) && of_node_get(np)) | |
323 | break; | |
324 | } | |
325 | of_node_put(from); | |
326 | read_unlock(&devtree_lock); | |
327 | return np; | |
328 | } | |
329 | EXPORT_SYMBOL(of_find_compatible_node); | |
283029d1 | 330 | |
1e291b14 ME |
331 | /** |
332 | * of_find_node_with_property - Find a node which has a property with | |
333 | * the given name. | |
334 | * @from: The node to start searching from or NULL, the node | |
335 | * you pass will not be searched, only the next one | |
336 | * will; typically, you pass what the previous call | |
337 | * returned. of_node_put() will be called on it | |
338 | * @prop_name: The name of the property to look for. | |
339 | * | |
340 | * Returns a node pointer with refcount incremented, use | |
341 | * of_node_put() on it when done. | |
342 | */ | |
343 | struct device_node *of_find_node_with_property(struct device_node *from, | |
344 | const char *prop_name) | |
345 | { | |
346 | struct device_node *np; | |
347 | struct property *pp; | |
348 | ||
349 | read_lock(&devtree_lock); | |
350 | np = from ? from->allnext : allnodes; | |
351 | for (; np; np = np->allnext) { | |
352 | for (pp = np->properties; pp != 0; pp = pp->next) { | |
353 | if (of_prop_cmp(pp->name, prop_name) == 0) { | |
354 | of_node_get(np); | |
355 | goto out; | |
356 | } | |
357 | } | |
358 | } | |
359 | out: | |
360 | of_node_put(from); | |
361 | read_unlock(&devtree_lock); | |
362 | return np; | |
363 | } | |
364 | EXPORT_SYMBOL(of_find_node_with_property); | |
365 | ||
283029d1 GL |
366 | /** |
367 | * of_match_node - Tell if an device_node has a matching of_match structure | |
368 | * @matches: array of of device match structures to search in | |
369 | * @node: the of device structure to match against | |
370 | * | |
371 | * Low level utility function used by device matching. | |
372 | */ | |
373 | const struct of_device_id *of_match_node(const struct of_device_id *matches, | |
374 | const struct device_node *node) | |
375 | { | |
376 | while (matches->name[0] || matches->type[0] || matches->compatible[0]) { | |
377 | int match = 1; | |
378 | if (matches->name[0]) | |
379 | match &= node->name | |
380 | && !strcmp(matches->name, node->name); | |
381 | if (matches->type[0]) | |
382 | match &= node->type | |
383 | && !strcmp(matches->type, node->type); | |
384 | if (matches->compatible[0]) | |
385 | match &= of_device_is_compatible(node, | |
386 | matches->compatible); | |
387 | if (match) | |
388 | return matches; | |
389 | matches++; | |
390 | } | |
391 | return NULL; | |
392 | } | |
393 | EXPORT_SYMBOL(of_match_node); | |
394 | ||
395 | /** | |
396 | * of_find_matching_node - Find a node based on an of_device_id match | |
397 | * table. | |
398 | * @from: The node to start searching from or NULL, the node | |
399 | * you pass will not be searched, only the next one | |
400 | * will; typically, you pass what the previous call | |
401 | * returned. of_node_put() will be called on it | |
402 | * @matches: array of of device match structures to search in | |
403 | * | |
404 | * Returns a node pointer with refcount incremented, use | |
405 | * of_node_put() on it when done. | |
406 | */ | |
407 | struct device_node *of_find_matching_node(struct device_node *from, | |
408 | const struct of_device_id *matches) | |
409 | { | |
410 | struct device_node *np; | |
411 | ||
412 | read_lock(&devtree_lock); | |
413 | np = from ? from->allnext : allnodes; | |
414 | for (; np; np = np->allnext) { | |
415 | if (of_match_node(matches, np) && of_node_get(np)) | |
416 | break; | |
417 | } | |
418 | of_node_put(from); | |
419 | read_unlock(&devtree_lock); | |
420 | return np; | |
421 | } | |
422 | EXPORT_SYMBOL(of_find_matching_node); | |
3f07af49 GL |
423 | |
424 | /** | |
425 | * of_modalias_table: Table of explicit compatible ==> modalias mappings | |
426 | * | |
427 | * This table allows particulare compatible property values to be mapped | |
428 | * to modalias strings. This is useful for busses which do not directly | |
429 | * understand the OF device tree but are populated based on data contained | |
430 | * within the device tree. SPI and I2C are the two current users of this | |
431 | * table. | |
432 | * | |
433 | * In most cases, devices do not need to be listed in this table because | |
434 | * the modalias value can be derived directly from the compatible table. | |
435 | * However, if for any reason a value cannot be derived, then this table | |
436 | * provides a method to override the implicit derivation. | |
437 | * | |
438 | * At the moment, a single table is used for all bus types because it is | |
439 | * assumed that the data size is small and that the compatible values | |
440 | * should already be distinct enough to differentiate between SPI, I2C | |
441 | * and other devices. | |
442 | */ | |
443 | struct of_modalias_table { | |
444 | char *of_device; | |
445 | char *modalias; | |
446 | }; | |
447 | static struct of_modalias_table of_modalias_table[] = { | |
4c3ed7d6 | 448 | { "fsl,mcu-mpc8349emitx", "mcu-mpc8349emitx" }, |
3f07af49 GL |
449 | }; |
450 | ||
451 | /** | |
452 | * of_modalias_node - Lookup appropriate modalias for a device node | |
453 | * @node: pointer to a device tree node | |
454 | * @modalias: Pointer to buffer that modalias value will be copied into | |
455 | * @len: Length of modalias value | |
456 | * | |
457 | * Based on the value of the compatible property, this routine will determine | |
58f467ce GL |
458 | * an appropriate modalias value for a particular device tree node. Two |
459 | * separate methods are attempted to derive a modalias value. | |
3f07af49 GL |
460 | * |
461 | * First method is to lookup the compatible value in of_modalias_table. | |
58f467ce GL |
462 | * Second is to strip off the manufacturer prefix from the first |
463 | * compatible entry and use the remainder as modalias | |
3f07af49 GL |
464 | * |
465 | * This routine returns 0 on success | |
466 | */ | |
467 | int of_modalias_node(struct device_node *node, char *modalias, int len) | |
468 | { | |
469 | int i, cplen; | |
470 | const char *compatible; | |
471 | const char *p; | |
472 | ||
473 | /* 1. search for exception list entry */ | |
474 | for (i = 0; i < ARRAY_SIZE(of_modalias_table); i++) { | |
475 | compatible = of_modalias_table[i].of_device; | |
476 | if (!of_device_is_compatible(node, compatible)) | |
477 | continue; | |
478 | strlcpy(modalias, of_modalias_table[i].modalias, len); | |
479 | return 0; | |
480 | } | |
481 | ||
482 | compatible = of_get_property(node, "compatible", &cplen); | |
483 | if (!compatible) | |
484 | return -ENODEV; | |
485 | ||
58f467ce | 486 | /* 2. take first compatible entry and strip manufacturer */ |
3f07af49 GL |
487 | p = strchr(compatible, ','); |
488 | if (!p) | |
489 | return -ENODEV; | |
490 | p++; | |
491 | strlcpy(modalias, p, len); | |
492 | return 0; | |
493 | } | |
494 | EXPORT_SYMBOL_GPL(of_modalias_node); | |
495 | ||
64b60e09 AV |
496 | /** |
497 | * of_parse_phandles_with_args - Find a node pointed by phandle in a list | |
498 | * @np: pointer to a device tree node containing a list | |
499 | * @list_name: property name that contains a list | |
500 | * @cells_name: property name that specifies phandles' arguments count | |
501 | * @index: index of a phandle to parse out | |
7736a3db AV |
502 | * @out_node: optional pointer to device_node struct pointer (will be filled) |
503 | * @out_args: optional pointer to arguments pointer (will be filled) | |
64b60e09 AV |
504 | * |
505 | * This function is useful to parse lists of phandles and their arguments. | |
506 | * Returns 0 on success and fills out_node and out_args, on error returns | |
507 | * appropriate errno value. | |
508 | * | |
509 | * Example: | |
510 | * | |
511 | * phandle1: node1 { | |
512 | * #list-cells = <2>; | |
513 | * } | |
514 | * | |
515 | * phandle2: node2 { | |
516 | * #list-cells = <1>; | |
517 | * } | |
518 | * | |
519 | * node3 { | |
520 | * list = <&phandle1 1 2 &phandle2 3>; | |
521 | * } | |
522 | * | |
523 | * To get a device_node of the `node2' node you may call this: | |
524 | * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args); | |
525 | */ | |
526 | int of_parse_phandles_with_args(struct device_node *np, const char *list_name, | |
527 | const char *cells_name, int index, | |
528 | struct device_node **out_node, | |
529 | const void **out_args) | |
530 | { | |
531 | int ret = -EINVAL; | |
532 | const u32 *list; | |
533 | const u32 *list_end; | |
534 | int size; | |
535 | int cur_index = 0; | |
536 | struct device_node *node = NULL; | |
7736a3db | 537 | const void *args = NULL; |
64b60e09 AV |
538 | |
539 | list = of_get_property(np, list_name, &size); | |
540 | if (!list) { | |
541 | ret = -ENOENT; | |
542 | goto err0; | |
543 | } | |
544 | list_end = list + size / sizeof(*list); | |
545 | ||
546 | while (list < list_end) { | |
547 | const u32 *cells; | |
548 | const phandle *phandle; | |
549 | ||
c1bb7c6d AV |
550 | phandle = list++; |
551 | args = list; | |
64b60e09 AV |
552 | |
553 | /* one cell hole in the list = <>; */ | |
c1bb7c6d | 554 | if (!*phandle) |
64b60e09 | 555 | goto next; |
64b60e09 AV |
556 | |
557 | node = of_find_node_by_phandle(*phandle); | |
558 | if (!node) { | |
559 | pr_debug("%s: could not find phandle\n", | |
560 | np->full_name); | |
561 | goto err0; | |
562 | } | |
563 | ||
564 | cells = of_get_property(node, cells_name, &size); | |
565 | if (!cells || size != sizeof(*cells)) { | |
566 | pr_debug("%s: could not get %s for %s\n", | |
567 | np->full_name, cells_name, node->full_name); | |
568 | goto err1; | |
569 | } | |
570 | ||
c1bb7c6d | 571 | list += *cells; |
64b60e09 AV |
572 | if (list > list_end) { |
573 | pr_debug("%s: insufficient arguments length\n", | |
574 | np->full_name); | |
575 | goto err1; | |
576 | } | |
577 | next: | |
578 | if (cur_index == index) | |
579 | break; | |
580 | ||
581 | of_node_put(node); | |
582 | node = NULL; | |
7736a3db | 583 | args = NULL; |
64b60e09 AV |
584 | cur_index++; |
585 | } | |
586 | ||
587 | if (!node) { | |
7736a3db AV |
588 | /* |
589 | * args w/o node indicates that the loop above has stopped at | |
590 | * the 'hole' cell. Report this differently. | |
591 | */ | |
592 | if (args) | |
593 | ret = -EEXIST; | |
594 | else | |
595 | ret = -ENOENT; | |
64b60e09 AV |
596 | goto err0; |
597 | } | |
598 | ||
7736a3db AV |
599 | if (out_node) |
600 | *out_node = node; | |
601 | if (out_args) | |
602 | *out_args = args; | |
64b60e09 AV |
603 | |
604 | return 0; | |
605 | err1: | |
606 | of_node_put(node); | |
607 | err0: | |
608 | pr_debug("%s failed with status %d\n", __func__, ret); | |
609 | return ret; | |
610 | } | |
611 | EXPORT_SYMBOL(of_parse_phandles_with_args); |